An inkjet printing system may include a printhead and an ink supply which supplies liquid ink to the printhead. The printhead ejects drops of the ink through a plurality of nozzles or orifices and toward a print medium, such as a sheet of paper, so as to print onto the print medium. Typically, the orifices are arranged in one or more arrays such that properly sequenced ejection of ink from the orifices causes characters or other images to be printed upon the print medium as the printhead and the print medium are moved relative to each other.
During use and/or non-use of the printhead, it is possible for the orifices to become clogged with ink and/or for bubbles of air to be trapped within the printhead in such a manner as to interfere with proper operation of the printhead. In addition, it is desirable to prevent ink from drying in the orifices when the printhead is not in use, and to clear out soft viscous plugs of ink which may form in the orifices when the printhead is not in use.
For these and other reasons, a need exists for the present invention.